Buckle device

Abstract

A buckle device which can ensure smooth unlocking over a long period of time at low cost. A button slope 66 is a curved surface opening toward a button 50 side with respect to an unlocking direction. Accordingly, the increasing amount of force of the button slopes 66 pressing abutted surfaces 86A with respect to the amount of movement of the button 50 is small immediately after the button 50 started to be pressed, and frictional resistance between the button slopes 66 and the abutted surfaces 86A can be thereby made smaller than before. Thus, wear of the abutted surfaces 86A can be reduced or prevented. For example, even when coatings are applied to the abutted surfaces 86A to reduce the frictional resistance between the button slopes 66 and the abutted surfaces 86A so that the unlocking can be smoothly carried out, degree of dependence on the coatings for reducing the frictional resistance becomes lower than before so that the coatings can be kept long. As a result, the unlocking can be smoothly carried out over a long period of time.

Description

TECHNICAL FIELD

[0001] The present invention relates to a buckle device, which, in a seat belt device for a vehicle, maintains a state in which a webbing belt restrains the body of a vehicle occupant.

BACKGROUND ART

[0002] A seat belt device for restraining, by an elongated webbing belt, the body of a vehicle occupant who is seated in a seat of a vehicle, comprises a so-called buckle device. The buckle device comprises a case, and is locked by passing a latch through a hole formed in a tongue plate provided at the webbing belt in a state in which the tongue plate is inserted into the case, so that the webbing belt is fastened to the vehicle occupant.

[0003] In order to release this locked state, a release button provided at the case is pressed. Button slopes having inclined surfaces are formed in the release button. When the release button is pressed and moved relatively to the case, the latch abuts against the inclined surfaces of the button slopes. Further, the release button is moved even more in the state in which the latch abuts against the inclined surfaces of the button slopes, the latch moves along the inclined surfaces and thereby separates from the tongue plate, so that the lock of the tongue plate by the latch is released.

[0004] As described above, when the release button is moved in the state in which the latch abuts against the inclined surfaces of the button slopes, friction causes between the latch and the inclined surfaces of the button slopes. In order to reduce frictional resistance therebetween so that the latch moves smoothly along the inclined surfaces of the button slopes, coatings are generally applied to the inclined surfaces of the button slopes and/or portions of the latch abutting against the inclined surfaces.

[0005] However, while the lock is repeatedly released, the coatings are deteriorated by the friction. In the state in which the coatings are deteriorated, the locking is released less smoothly than in the state in which the coatings are not deteriorated.

[0006] As a means for preventing the problem, the coatings may be simply thickened. However, the thickened coatings increase costs.

[0007] In view of the above facts, an object of the present invention is to obtain a buckle device which can ensure smooth unlocking over a long period of time at low cost.

DISCLOSURE OF THE INVENTION

[0008] In order to attain the above object, a buckle device of claim 1 comprises: a device body into which a tongue plate is insertable, the tongue plate being provided at a webbing belt for restraining an occupant body; a locking member, which is provided in the device body such that the locking member is movable toward and away from the tongue plate inserted into the device body, and which engages with the tongue plate to lock the tongue plate inserted into the device body; and an unlocking member, which moves relatively to the device body due to releasing operation from the outside of the device body, and on which the locking member slides at least during the relative movement and which presses the locking member with the relative movement so as to move the locking member in a direction in which the locking member separates from the tongue plate; wherein each of abutting portions of the unlocking member, on which the locking member slides, comprises plural inclined surfaces, which descend in a direction opposite to the direction in which the unlocking member moves relatively to the device body when the locking member is pressed so as to protrude in the direction in which the locking member is pressed, and which are sequent in the direction of the relative movement, and which relatively have larger angles of inclination in the direction of the relative movement.

[0009] In a buckle device of claim 2 according to the present invention of claim 1, the abutting portion comprises a curved surface formed by a sequence of innumerable extremely minute inclined surfaces.

[0010] In a buckle device of claim 3 according to the present invention of claim 2, an abutted portion of the unlocking member, the abutting portion contacts, comprises at least one of a curved surface and an inclined surface, a portion of which contacting the abutting portion varies with the relative movement.

[0011] In a buckle device of claim 4 according to the present invention of claim 3, the unlocking member comprises: a press portion, which is provided such that the press portion is slidable in the direction in which the tongue plate is inserted into the device body and in the opposite direction thereto, and which slides into the device body due to a pressing force along the insertion direction from the outside of the device body; a first urging member, which urges the locking member toward the tongue plate inserted into the device body; and stoppers, which interfere with the unlocked locking member in a state in which the press portion has not slid into the device body, so as to hold the locking member at the unlocked position.

[0012] In a buckle device of claim 5 according to the present invention of claim 4, the locking member includes a latch, which passes through a through-hole formed in the tongue plate so as to lock the tongue plate, and the device body comprises a holding member, which holds the latch such that the latch is slidable toward and away from the tongue plate along a thickness direction of the tongue plate inserted into the device body.

[0013] In a buckle device of claim 6 according to the present invention of claim 5, the holding member has a second urging member, which urges the unlocking member in a direction opposite to the direction in which the unlocking member moves when the lock of the tongue plate is released.

[0014] In a buckle device of claim 7 according to the present invention of claim 3, the locking member includes a latch, which passes through a through-hole formed in the tongue plate so as to lock the tongue plate, and the device body comprises a holding member, which holds the latch such that the latch is slidable toward and away from the tongue plate along a thickness direction of the tongue plate inserted into the device body.

[0015] In a buckle device of claim 8 according to the present invention of claim 7, the holding member has a second urging member, which urges the unlocking member in a direction opposite to the direction in which the unlocking member moves when the lock of the tongue plate is released.

[0016] In a buckle device of claim 9 according to the present invention of claim 3, the unlocking member comprises: a press portion, which is provided such that the press portion is slidable in the direction in which the tongue plate is inserted into the device body and in the opposite direction thereto, and which slides into the device body due to a pressing force along the insertion direction from the outside of the device body; a first urging member, which urges the locking member toward the tongue plate inserted into the device body; and stoppers, which interfere with the unlocked locking member in a state in which the press portion has not slid into the device body, so as to hold the locking member at the unlocked position.

[0017] In a buckle device of claim 10 according to the present invention of claim 9, the locking member includes a latch, which passes through a through-hole formed in the tongue plate so as to lock the tongue plate, and the device body comprises a holding member, which holds the latch such that the latch is slidable toward and away from the tongue plate along a thickness direction of the tongue plate inserted into the device body.

[0018] In a buckle device of claim 11 according to the present invention of claim 10, the holding member has a second urging member, which urges the unlocking member in a direction opposite to the direction in which the unlocking member moves when the lock of the tongue plate is released.

[0019] In a buckle device of claim 12 according to the present invention of claim 2, the locking member includes a latch, which passes through a through-hole formed in the tongue plate so as to lock the tongue plate, and the device body comprises a holding member, which holds the latch such that the latch is slidable toward and away from the tongue plate along a thickness direction of the tongue plate inserted into the device body.

[0020] In a buckle device of claim 13 according to the present invention of claim 12, the holding member has a second urging member, which urges the unlocking member in a direction opposite to the direction in which the unlocking member moves when the lock of the tongue plate is released.

[0021] In a buckle device of claim 14 according to the present invention of claim 1, an abutted portion of the unlocking member, the abutting portion contacts, comprises at least one of a curved surface and an inclined surface, a portion of which contacting the abutting portion varies with the relative movement.

[0022] In a buckle device of claim 15 according to the present invention of claim 14, the unlocking member comprises: a press portion, which is provided such that the press portion is slidable in the direction in which the tongue plate is inserted into the device body and in the opposite direction thereto, and which slides into the device body due to a pressing force along the insertion direction from the outside of the device body; a first urging member, which urges the locking member toward the tongue plate inserted into the device body; and stoppers, which interfere with the unlocked locking member in a state in which the press portion has not slid into the device body, so as to hold the locking member at the unlocked position.

[0023] In a buckle device of claim 16 according to the present invention of claim 15, the locking member includes a latch, which passes through a through-hole formed in the tongue plate so as to lock the tongue plate, and the device body comprises a holding member, which holds the latch such that the latch is slidable toward and away from the tongue plate along a thickness direction of the tongue plate inserted into the device body.

[0024] In a buckle device of claim 17 according to the present invention of claim 16, the holding member has a second urging member, which urges the unlocking member in a direction opposite to the direction in which the unlocking member moves when the lock of the tongue plate is released.

[0025] In a buckle device of claim 18 according to the present invention of claim 14, the locking member includes a latch, which passes through a through-hole formed in the tongue plate so as to lock the tongue plate, and the device body comprises a holding member, which holds the latch such that the latch is slidable toward and away from the tongue plate along a thickness direction of the tongue plate inserted into the device body.

[0026] In a buckle device of claim 19 according to the present invention of claim 18, the holding member has a second urging member, which urges the unlocking member in a direction opposite to the direction in which the unlocking member moves when the lock of the tongue plate is released.

[0027] In a buckle device of claim 20 according to the present invention of claim 1, the unlocking member comprises: a press portion, which is provided such that the press portion is slidable in the direction in which the tongue plate is inserted into the device body and in the opposite direction thereto, and which slides into the device body due to a pressing force along the insertion direction from the outside of the device body; a first urging member, which urges the locking member toward the tongue plate inserted into the device body; and stoppers, which interfere with the unlocked locking member in a state in which the press portion has not slid into the device body, so as to hold the locking member at the unlocked position.

[0028] In accordance with a buckle device relating to the present invention of claim 1, when the locking member provided in the device body engages with the tongue plate in a state in which the tongue plate is inserted into the device body, the tongue plate is locked by the locking member and restrained from moving in a direction in which the tongue plate is removed from the device body. Accordingly, the webbing belt provided with the tongue plate becomes in a fastened state so that an occupant body is restrained by the webbing belt.

[0029] When the unlocking member is operated from the outside of the device body in the locked state in which the locking member engages with the tongue plate, and thereby moved relatively to the device body, the abutting portions of the unlocking member abut against and press the locking member. The locking member moves, due to the pressing force, in a direction in which the locking member separates from the tongue plate, and thus, the lock of the tongue plate by the locking member is released so that the tongue plate can be removed from the device body.

[0030] In the buckle device of the present invention, each of the abutting portions of the unlocking member, on which the locking member slides, comprises plural inclined surfaces being sequent in the direction in which the unlocking member moves relatively to the device body when the locking member is pressed. The inclined surfaces descend in a direction opposite to the direction of the relative movement so as to protrude in the direction in which the locking member is pressed, and relatively have larger angles of inclination in the direction of the relative movement and face to the direction opposite to the direction of the relative movement.

[0031] Thus, immediately after the unlocking member started the relative movement, since the angle of inclination of the inclined surface forming the abutting portion is small, the distance at which the locking member moves due to the pressing force from the abutting portions is small. Thereafter, as the unlocking member relatively moves, the locking distance gradually increases and the distance at which the locking member moves gradually increases.

[0032] Since, in this manner, the amount of movement of the locking member is small immediately after the unlocking member started to move relatively to the device body, the pressing force, the abutting portions apply to the unlocking member at the time of starting to unlock, can be made small. As a result, frictional resistance between the abutting portions and the abutted portions at the time of starting to unlock becomes small.

[0033] Therefore, even if coating or the like is applied to the locking member and/or the unlocking member in order to reduce the frictional resistance between the abutting portions and the portions of the locking member contacting the abutting portions, degree of dependence on the coating or the like for reducing the frictional resistance can be made small, and thus, deterioration of the coating or the like can be prevented or reduced.

[0034] Although the abutting portion has a structure including a sequence of plural inclined surfaces in the present invention, the abutting portion is not limited to a planar surface in the present invention. In other words, since a curved surface is formed by a sequence of innumerable extremely minute inclined surfaces which have different angles of inclination from each other, even if the abutting portion is a curved surface, such a structure does not contradict the structure of the present invention according to claim 1.

[0035] The abutting portion of a buckle device relating to the present invention of claim 2 comprises a curved surface formed by a sequence of innumerable extremely minute inclined surfaces. When the abutting portion comprises a curved surface in this manner, rate of change for the angle of inclination along the direction, in which the unlocking member moves relatively to the device body when the locking member is pressed, is small. Accordingly, the pressing force applied from the abutting portions (the unlocking member) to the locking member does not change rapidly, and the locking member can be thereby moved smoothly.

[0036] In a buckle device relating to the present invention of claim 3, the abutted portion of the locking member corresponding to the abutting portion of the unlocking member comprises an inclined surface or a curved surface, and the portion of the abutted portion contacting the abutting portion varies with the movement of the unlocking member relative to the device body. Therefore, the portion where the friction between the abutting portion and the abutted portion causes basically varies all the time during unlocking. Accordingly, not only specific portions of the abutting portion and/or the abutted portion wear, and thus, even when the above-described coating or the like is applied, deterioration of the coating can be prevented or reduced even more.

[0037] In accordance with a buckle device relating to the present invention of claim 4, the stoppers are provided at the unlocking member. For example, in a state in which the tongue plate is not inserted into the device body, the stoppers interfere with the locking member so as to hold the locking member at the unlocked position.

[0038] When the tongue plate is inserted into the device body in this state to release the stoppers' interference with the locking member, the first urging member forming the unlocking member moves the locking member with the urging force thereof to engage the locking member with the tongue plate. As a result, the tongue plate is locked.

[0039] When the press portion of the unlocking member is pressed in the state in which the tongue plate is locked by the locking member, so that the unlocking member slides in the direction in which the tongue plate is inserted into the device body, the abutting portions move the locking member. Accordingly, the lock of the tongue plate is released, and the stoppers interfere with the locking member so as to hold the locking member at the unlocked position.

[0040] In accordance with a buckle device relating to the present invention of claim 5, the device body comprises the holding member, for example, provided therein, and the latch serving as the locking member is thereby held such that the latch is slidable along a thickness direction of the tongue plate inserted into the device body.

[0041] When the tongue plate is inserted into the device body and the latch slides toward the tongue plate, the latch passes through the through-hole formed in the tongue plate so as to lock the tongue plate.

[0042] In accordance with a buckle device relating to the present invention of claim 6, the holding member has the second urging member. The unlocking member is urged by the urging force of the second urging member in a direction opposite to the direction in which the unlocking member moves when the lock of the tongue plate is released.

[0043] Accordingly, unless the unlocking member moves against the urging force of the second urging member, the lock of the tongue plate is not released, and the buckle device can be thereby prevented from being inadvertently unlocked.

[0044] In accordance with a buckle device relating to the present invention of claim 7, the device body comprises the holding member, for example, provided therein, and the latch serving as the locking member is thereby held such that the latch is slidable along a thickness direction of the tongue plate inserted into the device body.

[0045] When the tongue plate is inserted into the device body and the latch slides toward the tongue plate, the latch passes through the through-hole formed in the tongue plate so as to lock the tongue plate.

[0046] In accordance with a buckle device relating to the present invention of claim 8, the holding member has the second urging member. The unlocking member is urged by the urging force of the second urging member in a direction opposite to the direction in which the unlocking member moves when the lock of the tongue plate is released.

[0047] Accordingly, unless the unlocking member moves against the urging force of the second urging member, the lock of the tongue plate is not released, and the buckle device can be thereby prevented from being inadvertently unlocked.

[0048] In accordance with a buckle device relating to the present invention of claim 9, the stoppers are provided at the unlocking member. For example, in a state in which the tongue plate is not inserted into the device body, the stoppers interfere with the locking member so as to hold the locking member at the unlocked position.

[0049] When the tongue plate is inserted into the device body in this state to release the stoppers' interference with the locking member, the first urging member forming the unlocking member moves the locking member with the urging force thereof to engage the locking member with the tongue plate. As a result, the tongue plate is locked.

[0050] When the press portion of the unlocking member is pressed in the state in which the tongue plate is locked by the locking member, so that the unlocking member slides in the direction in which the tongue plate is inserted into the device body, the abutting portions move the locking member. Accordingly, the lock of the tongue plate is released, and the stoppers interfere with the locking member so as to hold the locking member at the unlocked position.

[0051] In accordance with a buckle device relating to the present invention of claim 10, the device body comprises the holding member, for example, provided therein, and the latch serving as the locking member is thereby held such that the latch is slidable along a thickness direction of the tongue plate inserted into the device body.

[0052] When the tongue plate is inserted into the device body and the latch slides toward the tongue plate, the latch passes through the through-hole formed in the tongue plate so as to lock the tongue plate.

[0053] In accordance with a buckle device relating to the present invention of claim 11, the holding member has the second urging member. The unlocking member is urged by the urging force of the second urging member in a direction opposite to the direction in which the unlocking member moves when the lock of the tongue plate is released.

[0054] Accordingly, unless the unlocking member moves against the urging force of the second urging member, the lock of the tongue plate is not released, and the buckle device can be thereby prevented from being inadvertently unlocked.

[0055] In accordance with a buckle device relating to the present invention of claim 12, the device body comprises the holding member, for example, provided therein, and the latch serving as the locking member is thereby held such that the latch is slidable along a thickness direction of the tongue plate inserted into the device body.

[0056] When the tongue plate is inserted into the device body and the latch slides toward the tongue plate, the latch passes through the through hole formed in the tongue plate so as to lock the tongue plate.

[0057] In accordance with a buckle device relating to the present invention of claim 13, the holding member has the second urging member. The unlocking member is urged by the urging force of the second urging member in a direction opposite to the direction in which the unlocking member moves when the lock of the tongue plate is released.

[0058] Accordingly, unless the unlocking member moves against the urging force of the second urging member, the lock of the tongue plate is not released, and the buckle device can be thereby prevented from being inadvertently unlocked.

[0059] In a buckle device relating to the present invention of claim 14, the abutted portion of the locking member corresponding to the abutting portion of the unlocking member comprises an inclined surface or a curved surface, and the portion of the abutted portion contacting the abutting portion varies with the movement of the unlocking member relative to the device body. Therefore, the portion where the friction between the abutting portion and the abutted portion causes basically varies all the time during unlocking. Accordingly, not only specific portions of the abutting portion and/or the abutted portion wear, and thus, even when the above-described coating or the like is applied, deterioration of the coating can be prevented or reduced even more.

[0060] In accordance with a buckle device relating to the present invention of claim 15, the stoppers are provided at the unlocking member. For example, in a state in which the tongue plate is not inserted into the device body, the stoppers interfere with the locking member so as to hold the locking member at the unlocked position.

[0061] When the tongue plate is inserted into the device body in this state to release the stoppers' interference with the locking member, the first urging member forming the unlocking member moves the locking member with the urging force thereof to engage the locking member with the tongue plate. As a result, the tongue plate is locked.

[0062] When the press portion of the unlocking member is pressed in the state in which the tongue plate is locked by the locking member, so that the unlocking member slides in the direction in which the tongue plate is inserted into the device body, the abutting portions move the locking member. Accordingly, the lock of the tongue plate is released, and the stoppers interfere with the locking member so as to hold the locking member at the unlocked position.

[0063] In accordance with a buckle device relating to the present invention of claim 16, the device body comprises the holding member, for example, provided therein, and the latch serving as the locking member is thereby held such that the latch is slidable along a thickness direction of the tongue plate inserted into the device body.

[0064] When the tongue plate is inserted into the device body and the latch slides toward the tongue plate, the latch passes through the through-hole formed in the tongue plate so as to lock the tongue plate.

[0065] In accordance with a buckle device relating to the present invention of claim 17, the holding member has the second urging member. The unlocking member is urged by the urging force of the second urging member in a direction opposite to the direction in which the unlocking member moves when the lock of the tongue plate is released.

[0066] Accordingly, unless the unlocking member moves against the urging force of the second urging member, the lock of the tongue plate is not released, and the buckle device can be thereby prevented from being inadvertently unlocked.

[0067] In accordance with a buckle device relating to the present invention of claim 18, the device body comprises the holding member, for example, provided therein, and the latch serving as the locking member is thereby held such that the latch is slidable along a thickness direction of the tongue plate inserted into the device body.

[0068] When the tongue plate is inserted into the device body and the latch slides toward the tongue plate, the latch passes through the through-hole formed in the tongue plate so as to lock the tongue plate.

[0069] In accordance with a buckle device relating to the present invention of claim 19, the holding member has the second urging member. The unlocking member is urged by the urging force of the second urging member in a direction opposite to the direction in which the unlocking member moves when the lock of the tongue plate is released.

[0070] Accordingly, unless the unlocking member moves against the urging force of the second urging member, the lock of the tongue plate is not released, and the buckle device can be thereby prevented from being inadvertently unlocked.

[0071] In accordance with a buckle device relating to the present invention of claim 20, the stoppers are provided at the unlocking member. For example, in a state in which the tongue plate is not inserted into the device body, the stoppers interfere with the locking member so as to hold the locking member at the unlocked position.

[0072] When the tongue plate is inserted into the device body in this state to release the stoppers' interference with the locking member, the first urging member forming the unlocking member moves the locking member with the urging force thereof to engage the locking member with the tongue plate. As a result, the tongue plate is locked.

[0073] When the press portion of the unlocking member is pressed in the state in which the tongue plate is locked by the locking member, so that the unlocking member slides in the direction in which the tongue plate is inserted into the device body, the abutting portions move the locking member. Accordingly, the lock of the tongue plate is released, and the stoppers interfere with the locking member so as to hold the locking member at the unlocked position.

BRIEF DESCRIPTION OF THE DRAWINGS

[0074] FIG. 1 is a cross-sectional view of a buckle device in position according to an embodiment of the present invention.

[0075] FIG. 2 is a cross-sectional view showing a state of the buckle device locked by a locking member (a latch) in correspondence with FIG. 1.

[0076] FIG. 3 shows a positional relationship between the locking member (the latch) and an abutting portion (a button slope) immediately after starting to unlock.

[0077] FIG. 4 shows another positional relationship between the locking member (the latch) and the abutting portion (the button slope) in a state in which the locking member (the latch) has moved more than the state in FIG. 3.

[0078] FIG. 5 shows another positional relationship between the locking member (the latch) and the abutting portion (the button slope) in a state in which the locking member (the latch) has moved more than the state in FIG. 4.

[0079] FIG. 6 shows another positional relationship between the locking member (the latch) and the abutting portion (the button slope) in a state in which the locking member (the latch) has moved more than the state in FIG. 5.

[0080] FIG. 7 is an exploded perspective view of the buckle device according to the embodiment of the present invention.

[0081] FIG. 8 is a perspective view showing a modified example of the abutting portion (the button slope).

MOST PREFERRED EMBODIMENTS FOR IMPLEMENTING THE INVENTON

Structure of Present Embodiment

[0082] FIG. 1 is a cross-sectional view of a buckle device 10 in position according to an embodiment of the present invention, and FIG. 7 is an exploded perspective view of the buckle device 10.

[0083] As shown in FIG. 7, the buckle device 10 comprises a substantially box-shaped case 12 which is made of a synthetic resin. As shown in FIG. 1, one end of the case 12 in the longitudinal direction opens to form a slit opening 14 whose longitudinal direction is along the transverse direction of the case 12, and the other end of the case 12 in the longitudinal direction opens to form an opening 16.

[0084] The case 12 contains a buckle body 20 inside. The buckle body 20 comprises an anchor plate 26. The anchor plate 26 is formed by, for example, bending a plate member at the center thereof in the longitudinal direction so as to have a substantial U-shape, and the anchor plate 26 is contained inside the case 12 such that the opening end of the U-shape faces to the slit opening 14.

[0085] In the state in which the anchor plate 26 is contained in the case 12, space between an upper plate 28 and a lower plate 30 of the anchor plate 26, the plates 28 and 30 being opposite to each other in the vertical direction of the case 12, forms an insertion portion 34. Further, at a bottom portion of the anchor plate 26 bent in the U-shape, i.e., at the end of the anchor plate 26 on the opening 16 side, a slit-shaped insertion hole 32, whose longitudinal direction is along the transverse direction of the anchor plate 26, is formed in correspondence with a tongue plate 36.

[0086] A base end of the tongue plate 36 has a substantially slit-shaped insertion hole through which an elongated webbing belt is inserted, and a leading end of the tongue plate 36 slides through the insertion hole 32 into the space between the upper plate 28 and the lower plate 30, i.e., into the insertion portion 34.

[0087] As shown in FIG. 7, one end of a plate-shaped attachment piece 22 is inserted into the space between the upper plate 28 and the lower plate 30 from the opening end side of the anchor plate 26 bent in the U-shape, i.e., from the slit opening 14 side of the anchor plate 26. The other end of the attachment piece 22 is fixed to a vehicle at a side of a seat (e.g., driver seat or passenger seat) provided inside the vehicle. The one end of the attachment piece 22 inserted into the space between the upper plate 28 and the lower plate 30 is fastened and fixed to at least one of the upper plate 28 and the lower plate 30 by rivets 24, so that the anchor plate 26 is attached to the vehicle.

[0088] An ejector 38 is contained inside the anchor plate 26 such that the ejector 38 can slide along the longitudinal directions of the anchor plate 26 (the direction of arrow A in FIGS. 1 and 2 and the opposite direction thereto). An eject spring 40 is disposed between the ejector 38 and the attachment piece 22 to urge the ejector 38 toward the insertion hole 32 side (the direction opposite to arrow A in FIGS. 1 and 2).

[0089] Further, at both ends of the ejector 38 in the transverse direction, a pair of horn pieces 42 extend toward the attachment piece 22 side (i.e., toward the slit opening 14 side of the case 12). Abutment portions 46 are respectively formed near tips of the horn pieces 42. In correspondence with the abutment portions 46, protrusions are formed in the anchor plate 26 so as to protrude into the insertion portion 34. The protrusions correspondingly interfere with the abutment portions 46 to limit the slide of the ejector 38 within a predetermined range.

[0090] As shown in FIGS. 1 and 7, a button 50 forming an unlocking member is disposed on the upper plate 28 of the anchor plate 26. The button 50 is wholly formed in a substantially rectangular frame-shape in a plan view. The button 50 comprises an operation portion 52. The operation portion 52 has a pressing surface facing to the opening 16 side. The pressing surface is pressed so that the button 50 can be moved to the slit opening 14 side.

[0091] A pair of outer plates 54 extend parallel with each other from a side of the operation portion 52 opposite to the pressing surface (i.e., from the slit opening 14 side). Each of the outer plates 54 is formed in a substantial plate-shape whose thickness direction is along the transverse direction of the anchor plate 26. The outer plates 54 are opposite to each other in the transverse direction of the anchor plate 26.

[0092] Pawl pieces 62 extending toward the inner side are respectively formed at the outer plates 54. The pawl pieces 62 can engage with portions between the upper plate 28 and the lower plate 30 of the anchor plate 26 from outer sides of the anchor plate 26. In the state in which the pawl pieces 62 engage with the anchor plate 26, the button 50 cannot be released from the anchor plate 26 and can be slid along the longitudinal directions of the anchor plate 26 (the direction of arrow A in FIGS. 1 and 7 and the opposite direction thereto).

[0093] A pair of inner plates 58 are respectively provided on inner sides of the outer plates 54. The inner plates 58 extend parallel with each other from the side of the operation portion 52 opposite to the pressing surface (i.e., from the slit opening 14 side) in the same manner as the outer plates 54. Each of the inner plates 58 is formed in a substantial plate-shape whose thickness direction is along the transverse direction of the anchor plate 26. The inner plates 58 are opposite to each other in the transverse direction of the anchor plate 26.

[0094] Stoppers 64 are respectively formed on inner surfaces of the inner plates 58 (i.e., a stopper 64 is formed on a surface of one inner plate 58 on the opposite other inner plate 58 side, respectively). In the state in which the tongue plate 36 is not inserted into the insertion portion 34, the stoppers 64 abut against a latch 84 serving as a locking member, which will be described later, so as to prevent the latch 84 from moving in an engaging direction (the direction of arrow B in FIGS. 1 and 7). Further, in the state in which the tongue plate 36 is inserted into the insertion portion 34 and the latch 84 engages with an engagement hole 88 of the tongue plate 36 (locked state: see FIG. 2), the stoppers 64 respectively abut against upper surfaces of abutted pieces 86 of the latch 84 so as to prevent the latch 84 from moving in a disengaging direction (the direction opposite to arrow B in FIGS. 1 and 7).

[0095] Button slopes 66 serving as abutting portions are respectively formed on the inner surfaces of the inner plates 58 on the operation portion 52 side with respect to the stoppers 64. The button slope 66 descends toward the side opposite to the operation portion 52 (i.e., the slit opening 14 side) so as to protrude toward the side opposite to the anchor plate 26. A surface of the button slope 66 facing to the side opposite to the anchor plate 26 gradually separates from the anchor plate 26 toward the operation portion 52 side.

[0096] When the button 50 moves in an unlocking direction (the direction of arrow A in FIGS. 1 and 7) in the locked state, the button slopes 66 convert the pressing force to force which moves the latch 84 in the disengaging direction (the direction opposite to arrow B in FIGS. 1 and 7), and push abutted surfaces 86A serving as abutted portions of the abutted pieces 86 from lower sides thereof. Accordingly, the latch 84 moves in the disengaging direction.

[0097] In this embodiment, the button slope 66 is not a planar surface but a curved surface opening toward the button 50 side with respect to the unlocking direction. Therefore, the angle of inclination of the button slope 66 with respect to the unlocking direction varies depending upon portions of the button slope 66 along the unlocking direction, and decreases in the unlocking direction.

[0098] The above-described abutted surface 86A for contacting the button slope 66 is a curved surface projecting toward the button slope 66 side. The curvature of the abutted surface 86A is smaller than that of the button slope 66.

[0099] On the upper plate 28, a holding block 80 serving as a holding member, which straddles the inner plates 58, is disposed upright at a position which is more inward than the outer plates 54 of the button 50. The holding block 80 has a pair of parallel holding plates 82, between which the latch 84 is disposed. The holding plates 82 prevent the latch 84 from moving in the longitudinal directions of the anchor plate 26 (the direction of arrow A in FIGS. 1 and 7 and the opposite direction thereto), and allow the latch 84 to move in the engaging and disengaging directions (the direction of arrow B in FIGS. 1 and 7 and the opposite direction thereto).

[0100] The latch 84 is formed in a substantial U-shape in a front view, and the abutted pieces 86 extend from upper ends thereof toward outer sides in the transverse direction. Further, an engagement piece 90 extends from the center of the latch 84 in the transverse direction toward the anchor plate 26. When the tongue plate 36 is inserted into the insertion portion 34 up to a predetermined position, the engagement piece 90 passes through a through hole 92 formed in the upper plate 28 of the anchor plate 26, engages with the engagement hole 88 of the tongue plate 36, and further passes through a through hole 94 (see FIG. 2) formed in the lower plate 30.

[0101] A pair of plate spring pieces 96 serving as second urging members extend from the holding block 80 toward the operation portion 52 of the button 50, and urge the button 50 toward the opening 16 side. Accordingly, when the operation portion 52 is pressed, appropriate resistance causes. Although the second urging members are formed by the plate spring pieces 96 in this embodiment, the second urging members may be any unlocking members, i.e., any members that can urge the button 50 toward the opening 16 side in this embodiment, and are not limited to specific embodiments. Thus, coil springs may be used in place of the plate springs 96.

[0102] Leg portions 68 are respectively formed to protrude from ends of the above-described inner plates 58 on the slit opening 14 side toward the anchor plate 26. The leg portions 68 respectively pass through elongated holes 70 formed in the upper plate 28, and locate between the upper plate 28 and the lower plate 30. The longitudinal direction of the elongated hole 70 is along the direction in which the button 50 slides. When the button 50 slides, the leg portions 68 move along the elongated holes 70. Similarly, when the leg portions 68 move along the elongated holes 70, the button 50 slides.

[0103] The leg portions 68 passing through the elongated holes 70 locate on a track of the tongue plate 36 moving between the upper plate 28 and the lower plate 30. When the tongue plate 36 has reached a predetermined position between the upper plate 28 and the lower plate 30, the ejector 38 abuts against the leg portions 68. Further, when the tongue plate 36 slides even more in this state, the leg portions 68 are pressed by the ejector 38 to move.

[0104] Further, one end of a plate spring-shaped lock spring 98 forming an unlocking member as a first urging member is attached to the button 50. The other end of the lock spring 98 abuts against an upper surface of the latch 84 to urge the latch 84 in the engaging direction (the direction of arrow B in FIGS. 1 and 7).

Operation and Effect of the Present Embodiment

[0105] Next, operation and effect of the present embodiment will be described.

[0106] In the buckle device 10 having the above-described structure, in the state in which the tongue plate 36 is not inserted into the insertion portion 34, the stoppers 64 of the button 50 abut against the abutted pieces 86 of the latch 84 from the lower side thereof, and thus, the latch 84 does not move in the engaging direction (the direction of arrow B in FIGS. 1 and 7) by the urging force of the lock spring 98.

[0107] When the tongue plate 36 is inserted into the insertion portion 34, the tongue plate 36 engages with the ejector 38 and presses it so that the ejector 38 slides against the urging force of the eject spring 40. Further, when the ejector 38 slides up to a predetermined position, the ejector 38 abuts against the leg portions 68 of the button 50, and presses and moves the leg portions 68.

[0108] When the leg portions 68 move, the stoppers 64 of the button 50 separate from the abutted pieces 86 of the latch 84. Therefore, the latch 84 moves in the engaging direction (the direction of arrow B in FIGS. 1 and 7) by receiving the urging force of the lock spring 98, and, as shown in FIG. 2, the engagement piece 90 of the latch 84 passes through the through hole 92 of the upper plate 28 and engages with the engagement hole 88 of the tongue plate 36. The button 50 is pressed by the plate spring pieces 96 and moved in the direction opposite to arrow A in FIGS. 1 and 7 so as to be in the locked state. In this state, the stoppers 64 of the button 50 abut against the abutted pieces 86 of the latch 84 from the upper side thereof so as to prevent the latch 84 from moving in the disengaging direction (the direction opposite to arrow B in FIG. 2). In the locked state, the tongue plate 36 is restrained from being removed from the insertion portion 34 (the case 12) by the engagement piece 90 of the latch 84.

[0109] When the operation portion 52 of the button 50 is pressed in this state inside the case 12 in the direction of arrow A in FIG. 2, the state in which the stoppers 64 and the abutted pieces 86 face to each other is released first. When the state in which the stoppers 64 and the abutted pieces 86 face to each other is released, as shown in FIGS. 3 to 6, the abutted surface 86A of the abutted piece 86 abutting against the button slope 66 is guided along the button slope 66 by the pressing force therefrom against the urging force from the lock spring 98, while the abutted piece 86 moves upward, i.e., in the direction in which the abutted piece 86 separates from the tongue plate 36. The movement of the abutted pieces 86 allows the latch 84 to come out of the engagement hole 88 first.

[0110] As shown in FIG. 1, when the latch 84 comes out of the engagement hole 88, it becomes possible that the tongue plate 36 comes out of the insertion portion 34. When the ejector 38 receiving the urging force of the eject spring 40 presses the tongue plate 36 in this state, the tongue plate 36 comes out of the insertion portion 34. Further, when the pressing force applied to the operation portion 52 of the button 50 is released in this state, the button 50 returns, by the urging force of the plate spring pieces 96, to the former position where the pressing force is not applied thereto. As a result, the stoppers 64 of the button 50 abut against the abutted pieces 86 of the latch 84 again from the lower side thereof so that the latch 84 is held.

[0111] As described above, in this buckle device 10, the button slope 66 is not a planar surface but a curved surface opening toward the button 50 side with respect to the unlocking direction. The angle of inclination of the button slope 66 with respect to the unlocking direction decreases in the unlocking direction. Therefore, although frictional resistance between the button slopes 66 and the abutted surfaces 86A is relatively high, in general, immediately after the button 50 (outer plates 54) started to be pressed, since the angle of inclination of this button slope 66 decreases in the unlocking direction, the amount of upward movement of the abutted surface 86A is relatively small immediately after the button 50 (outer plates 54) started to be pressed.

[0112] Accordingly, the increasing amount of the force of the button slopes 66 pressing the abutted surfaces 86A with respect to the amount of movement of the button 50 is small, and the frictional resistance between the button slopes 66 and the abutted surfaces 86A can be thereby made smaller than before. Thus, wear of the abutted surfaces 86A can be reduced or prevented. For example, even when coatings are applied to the abutted surfaces 86A to reduce the frictional resistance between the button slopes 66 and the abutted surfaces 86A so that the unlocking can be smoothly carried out, degree of dependence on the coatings for reducing the frictional resistance becomes lower than before so that the coatings can be kept long. As a result, the unlocking can be smoothly carried out over a long period of time.

[0113] Further, since the coatings do not need to be thickened in order to keep the smooth unlocking operation over a long period of time, the cost is low.

[0114] As described above, in this buckle device 10, the abutted surface 86A is a curved surface which projects toward the button slope 66 side and the curvature of which is smaller than that of the abutted surface 86A. Therefore, as shown in FIGS. 3 to 6, the portion of the abutted surface 86A contacting the button slope 66 when the abutted piece 86 moves along the button slope 66 varies depending upon positions of the abutted piece 86 on the button slope 66. Accordingly, not only one portion of the abutted surface 86A always contacts the button slope 66, and hence, even if the abutted surface 86A wears, the substantially entire abutted surface 86A wears uniformly. Thus, when a coating is applied to the abutted surface 86A, the coating can wear uniformly, and early considerable wear of one portion thereof can be prevented. As a result, effect of the coating can be kept over a long period of time.

[0115] In this embodiment, the button slope 66 serving as an abutting portion is a curved surface. However, as shown in FIG. 8, the button slope 66 may be formed by a sequence of planar inclined surfaces which relatively have smaller angles of inclination in the unlocking direction.

INDUSTRIAL APPLICABILITY

[0116] As described above, the buckle device according to the present invention is available not only for a buckle device forming a seat belt device for a vehicle but also for a buckle device forming a seat belt device for things other than a vehicle, without being limited to a specific embodiment of the seat belt device.

Claims

1. A buckle device comprising:

a device body into which a tongue plate is insertable, the tongue plate being provided at a webbing belt for restraining an occupant body;

a locking member, which is provided in said device body such that the locking member is movable toward and away from the tongue plate inserted into said device body, and which engages with the tongue plate to lock the tongue plate inserted into said device body; and

an unlocking member, which moves relatively to said device body due to releasing operation from the outside of said device body, and on which said locking member slides at least during the relative movement and which presses said locking member with the relative movement so as to move said locking member in a direction in which said locking member separates from the tongue plate;

wherein each of abutting portions of said unlocking member, on which said locking member slides, comprises a curved surface, which descends in a releasing operation direction which is the direction in which said unlocking member moves when the lock is released, so as to protrude in a release direction which is the direction in which said locking member moves when the lock is released, and whose angle of inclination with respect to the releasing operation direction increases in a direction opposite to the releasing operation direction.

2. Canceled

3. A buckle device according to claim 1, wherein an abutted portion of said unlocking member, said abutting portion contacts, comprises at least one of a curved surface and an inclined surface, a portion of which contacting said abutting portion varies with the relative movement.

4. A buckle device according to claim 3, wherein said unlocking member comprises:

a press portion, which is provided such that the press portion is slidable in the direction in which said tongue plate is inserted into said device body and in the opposite direction thereto, and which slides into said device body due to a pressing force along the insertion direction from the outside of said device body;

a first urging member, which urges said locking member toward said tongue plate inserted into said device body; and

stoppers, which interfere with the unlocked locking member in a state in which said press portion has not slid into said device body, so as to hold said locking member at the unlocked position.

5. A buckle device according to claim 4, wherein

said locking member includes a latch, which passes through an engagement hole formed in said tongue plate so as to lock said tongue plate, and

said device body comprises a holding member, which holds said latch such that said latch is slidable toward and away from said tongue plate along a thickness direction of said tongue plate inserted into said device body.

6. A buckle device according to claim 5, wherein said holding member has a second urging member, which urges said unlocking member in a direction opposite to the direction in which said unlocking member moves when the lock of said tongue plate is released.

7. A buckle device according to claim 3, wherein

said locking member includes a latch, which passes through an engagement hole formed in said tongue plate so as to lock said tongue plate, and

said device body comprises a holding member, which holds said latch such that said latch is slidable toward and away from said tongue plate along a thickness direction of said tongue plate inserted into said device body.

8. A buckle device according to claim 7, wherein said holding member has a second urging member, which urges said unlocking member in a direction opposite to the direction in which said unlocking member moves when the lock of said tongue plate is released.

9. A buckle device according to claim 1, wherein said unlocking member comprises:

a press portion, which is provided such that the press portion is slidable in the direction in which said tongue plate is inserted into said device body and in the opposite direction thereto, and which slides into said device body due to a pressing force along the insertion direction from the outside of said device body;

a first urging member, which urges said locking member toward said tongue plate inserted into said device body; and

stoppers, which interfere with the unlocked locking member in a state in which said press portion has not slid into said device body, so as to hold said locking member at the unlocked position.

10. A buckle device according to claim 9, wherein

said locking member includes a latch, which passes through an engagement hole formed in said tongue plate so as to lock said tongue plate, and

said device body comprises a holding member, which holds said latch such that said latch is slidable toward and away from said tongue plate along a thickness direction of said tongue plate inserted into said device body.

11. A buckle device according to claim 10, wherein said holding member has a second urging member, which urges said unlocking member in a direction opposite to the direction in which said unlocking member moves when the lock of said tongue plate is released.

12. A buckle device according to claim 1, wherein

said locking member includes a latch, which passes through an engagement hole formed in said tongue plate so as to lock said tongue plate, and

said device body comprises a holding member, which holds said latch such that said latch is slidable toward and away from said tongue plate along a thickness direction of said tongue plate inserted into said device body.

13. A buckle device according to claim 12, wherein said holding member has a second urging member, which urges said unlocking member in a direction opposite to the direction in which said unlocking member moves when the lock of said tongue plate is released.

14. Canceled

15. Canceled

16. Canceled

17. Canceled

18. Canceled

19. Canceled

20. Canceled